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2024-01-04um: document arch_futex_atomic_op_inuserGravatar Anton Ivanov 1-1/+3
arch_futex_atomic_op_inuser was not documented correctly resulting in build time warnings. Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2023-04-20um: make stub data pages size tweakableGravatar Johannes Berg 2-5/+6
There's a lot of code here that hard-codes that the data is a single page, and right now that seems to be sufficient, but to make it easier to change this in the future, add a new STUB_DATA_PAGES constant and use it throughout the code. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2023-02-05kbuild: remove --include-dir MAKEFLAG from top MakefileGravatar Masahiro Yamada 1-1/+1
I added $(srctree)/ to some included Makefiles in the following commits: - 3204a7fb98a3 ("kbuild: prefix $(srctree)/ to some included Makefiles") - d82856395505 ("kbuild: do not require sub-make for separate output tree builds") They were a preparation for removing --include-dir flag. I have never thought --include-dir useful. Rather, it _is_ harmful. For example, run the following commands: $ make -s ARCH=x86 mrproper defconfig $ make ARCH=arm O=foo dtbs make[1]: Entering directory '/tmp/linux/foo' HOSTCC scripts/basic/fixdep Error: kernelrelease not valid - run 'make prepare' to update it UPD include/config/kernel.release make[1]: Leaving directory '/tmp/linux/foo' The first command configures the source tree for x86. The next command tries to build ARM device trees in the separate foo/ directory - this must stop because the directory foo/ has not been configured yet. However, due to --include-dir=$(abs_srctree), the top Makefile includes the wrong include/config/auto.conf from the source tree and continues building. Kbuild traverses the directory tree, but of course it does not work correctly. The Error message is also pointless - 'make prepare' does not help at all for fixing the issue. This commit fixes more arch Makefile, and finally removes --include-dir from the top Makefile. There are more breakages under drivers/, but I do not volunteer to fix them all. I just moved --include-dir to drivers/Makefile. With this commit, the second command will stop with a sensible message. $ make -s ARCH=x86 mrproper defconfig $ make ARCH=arm O=foo dtbs make[1]: Entering directory '/tmp/linux/foo' SYNC include/config/auto.conf.cmd *** *** The source tree is not clean, please run 'make ARCH=arm mrproper' *** in /tmp/linux *** make[2]: *** [../Makefile:646: outputmakefile] Error 1 /tmp/linux/Makefile:770: include/config/auto.conf.cmd: No such file or directory make[1]: *** [/tmp/linux/Makefile:793: include/config/auto.conf.cmd] Error 2 make[1]: Leaving directory '/tmp/linux/foo' make: *** [Makefile:226: __sub-make] Error 2 Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-01-11Merge tag 'locking_core_for_v5.17_rc1' of ↵Gravatar Linus Torvalds 1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Borislav Petkov: "Lots of cleanups and preparation. Highlights: - futex: Cleanup and remove runtime futex_cmpxchg detection - rtmutex: Some fixes for the PREEMPT_RT locking infrastructure - kcsan: Share owner_on_cpu() between mutex,rtmutex and rwsem and annotate the racy owner->on_cpu access *once*. - atomic64: Dead-Code-Elemination" [ Description above by Peter Zijlstra ] * tag 'locking_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/atomic: atomic64: Remove unusable atomic ops futex: Fix additional regressions locking: Allow to include asm/spinlock_types.h from linux/spinlock_types_raw.h x86/mm: Include spinlock_t definition in pgtable. locking: Mark racy reads of owner->on_cpu locking: Make owner_on_cpu() into <linux/sched.h> lockdep/selftests: Adapt ww-tests for PREEMPT_RT lockdep/selftests: Skip the softirq related tests on PREEMPT_RT lockdep/selftests: Unbalanced migrate_disable() & rcu_read_lock(). lockdep/selftests: Avoid using local_lock_{acquire|release}(). lockdep: Remove softirq accounting on PREEMPT_RT. locking/rtmutex: Add rt_mutex_lock_nest_lock() and rt_mutex_lock_killable(). locking/rtmutex: Squash self-deadlock check for ww_rt_mutex. locking: Remove rt_rwlock_is_contended(). sched: Trigger warning if ->migration_disabled counter underflows. futex: Fix sparc32/m68k/nds32 build regression futex: Remove futex_cmpxchg detection futex: Ensure futex_atomic_cmpxchg_inatomic() is present kernel/locking: Use a pointer in ww_mutex_trylock().
2021-12-22um: remove set_fsGravatar Christoph Hellwig 1-25/+0
Remove address space overrides using set_fs() for User Mode Linux. Note that just like the existing kernel access case of the uaccess routines the new nofault kernel handlers do not actually have any exception handling. This is probably broken, but not change to the status quo. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Richard Weinberger <richard@nod.at>
2021-11-25futex: Remove futex_cmpxchg detectionGravatar Arnd Bergmann 1-1/+0
Now that all architectures have a working futex implementation in any configuration, remove the runtime detection code. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Acked-by: Vineet Gupta <vgupta@kernel.org> Acked-by: Max Filippov <jcmvbkbc@gmail.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Link: https://lore.kernel.org/r/20211026100432.1730393-2-arnd@kernel.org
2021-09-09Merge tag 'for-linus-5.15-rc1' of ↵Gravatar Linus Torvalds 1-2/+1
git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml Pull UML updates from Richard Weinberger: - Support for VMAP_STACK - Support for splice_write in hostfs - Fixes for virt-pci - Fixes for virtio_uml - Various fixes * tag 'for-linus-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: fix stub location calculation um: virt-pci: fix uapi documentation um: enable VMAP_STACK um: virt-pci: don't do DMA from stack hostfs: support splice_write um: virtio_uml: fix memory leak on init failures um: virtio_uml: include linux/virtio-uml.h lib/logic_iomem: fix sparse warnings um: make PCI emulation driver init/exit static
2021-08-26um: fix stub location calculationGravatar Johannes Berg 1-2/+1
In commit 9f0b4807a44f ("um: rework userspace stubs to not hard-code stub location") I changed stub_segv_handler() to do a calculation with a pointer to a stack variable to find the data page that we're using for the stack and the rest of the data. This same commit was meant to do it as well for stub_clone_handler(), but the change inadvertently went into commit 84b2789d6115 ("um: separate child and parent errors in clone stub") instead. This was reported to not be compiled correctly by gcc 5, causing the code to crash here. I'm not sure why, perhaps it's UB because the var isn't initialized? In any case, this trick always seemed bad, so just create a new inline function that does the calculation in assembly. Reported-by: subashab@codeaurora.org Fixes: 9f0b4807a44f ("um: rework userspace stubs to not hard-code stub location") Fixes: 84b2789d6115 ("um: separate child and parent errors in clone stub") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2021-07-23asm-generic/uaccess.h: remove __strncpy_from_user/__strnlen_userGravatar Arnd Bergmann 1-4/+10
This is a preparation for changing over architectures to the generic implementation one at a time. As there are no callers of either __strncpy_from_user() or __strnlen_user(), fold these into the strncpy_from_user() and strnlen_user() functions to make each implementation independent of the others. Many of these implementations have known bugs, but the intention here is to not change behavior at all and stay compatible with those bugs for the moment. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2021-07-09Merge tag 'for-linus-5.14-rc1' of ↵Gravatar Linus Torvalds 2-1/+137
git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml Pull UML updates from Richard Weinberger: - Support for optimized routines based on the host CPU - Support for PCI via virtio - Various fixes * tag 'for-linus-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: remove unneeded semicolon in um_arch.c um: Remove the repeated declaration um: fix error return code in winch_tramp() um: fix error return code in slip_open() um: Fix stack pointer alignment um: implement flush_cache_vmap/flush_cache_vunmap um: add a UML specific futex implementation um: enable the use of optimized xor routines in UML um: Add support for host CPU flags and alignment um: allow not setting extra rpaths in the linux binary um: virtio/pci: enable suspend/resume um: add PCI over virtio emulation driver um: irqs: allow invoking time-travel handler multiple times um: time-travel/signals: fix ndelay() in interrupt um: expose time-travel mode to userspace side um: export signals_enabled directly um: remove unused smp_sigio_handler() declaration lib: add iomem emulation (logic_iomem) um: allow disabling NO_IOMEM
2021-06-17um: Fix stack pointer alignmentGravatar YiFei Zhu 1-1/+1
GCC assumes that stack is aligned to 16-byte on call sites [1]. Since GCC 8, GCC began using 16-byte aligned SSE instructions to implement assignments to structs on stack. When CC_OPTIMIZE_FOR_PERFORMANCE is enabled, this affects os-Linux/sigio.c, write_sigio_thread: struct pollfds *fds, tmp; tmp = current_poll; Note that struct pollfds is exactly 16 bytes in size. GCC 8+ generates assembly similar to: movdqa (%rdi),%xmm0 movaps %xmm0,-0x50(%rbp) This is an issue, because movaps will #GP if -0x50(%rbp) is not aligned to 16 bytes [2], and how rbp gets assigned to is via glibc clone thread_start, then function prologue, going though execution trace similar to (showing only relevant instructions): sub $0x10,%rsi mov %rcx,0x8(%rsi) mov %rdi,(%rsi) syscall pop %rax pop %rdi callq *%rax push %rbp mov %rsp,%rbp The stack pointer always points to the topmost element on stack, rather then the space right above the topmost. On push, the pointer decrements first before writing to the memory pointed to by it. Therefore, there is no need to have the stack pointer pointer always point to valid memory unless the stack is poped; so the `- sizeof(void *)` in the code is unnecessary. On the other hand, glibc reserves the 16 bytes it needs on stack and pops itself, so by the call instruction the stack pointer is exactly the caller-supplied sp. It then push the 16 bytes of the return address and the saved stack pointer, so the base pointer will be 16-byte aligned if and only if the caller supplied sp is 16-byte aligned. Therefore, the caller must supply a 16-byte aligned pointer, which `stack + UM_KERN_PAGE_SIZE` already satisfies. On a side note, musl is unaffected by this issue because it forces 16 byte alignment via `and $-16,%rsi` in its clone wrapper. Similarly, glibc i386 is also unaffected because it has `andl $0xfffffff0, %ecx`. To reproduce this bug, enable CONFIG_UML_RTC and CC_OPTIMIZE_FOR_PERFORMANCE. uml_rtc will call add_sigio_fd which will then cause write_sigio_thread to either go into segfault loop or panic with "Segfault with no mm". Similarly, signal stacks will be aligned by the host kernel upon signal delivery. `- sizeof(void *)` to sigaltstack is unconventional and extraneous. On a related note, initialization of longjmp buffers do require `- sizeof(void *)`. This is to account for the return address that would have been pushed to the stack at the call site. The reason for uml to respect 16-byte alignment, rather than telling GCC to assume 8-byte alignment like the host kernel since commit d9b0cde91c60 ("x86-64, gcc: Use -mpreferred-stack-boundary=3 if supported"), is because uml links against libc. There is no reason to assume libc is also compiled with that flag and assumes 8-byte alignment rather than 16-byte. [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=40838 [2] https://c9x.me/x86/html/file_module_x86_id_180.html Signed-off-by: YiFei Zhu <zhuyifei1999@gmail.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Richard Weinberger <richard@nod.at>
2021-06-17um: add a UML specific futex implementationGravatar Anton Ivanov 1-0/+136
The generic asm futex implementation emulates atomic access to memory by doing a get_user followed by put_user. These translate to two mapping operations on UML with paging enabled in the meantime. This, in turn may end up changing interrupts, invoking the signal loop, etc. This replaces the generic implementation by a mapping followed by an operation on the mapped segment. Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2021-05-20x86/syscalls: Use __NR_syscalls instead of __NR_syscall_maxGravatar Masahiro Yamada 1-1/+1
__NR_syscall_max is only used by x86 and UML. In contrast, __NR_syscalls is widely used by all the architectures. Convert __NR_syscall_max to __NR_syscalls and adjust the usage sites. This prepares x86 to switch to the generic syscallhdr.sh script. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210517073815.97426-6-masahiroy@kernel.org
2021-02-12um: remove process stub VMAGravatar Johannes Berg 1-87/+0
This mostly reverts the old commit 3963333fe676 ("uml: cover stubs with a VMA") which had added a VMA to the existing PTEs. However, there's no real reason to have the PTEs in the first place and the VMA cannot be 'fixed' in place, which leads to bugs that userspace could try to unmap them and be forcefully killed, or such. Also, there's a bit of an ugly hole in userspace's address space. Simplify all this: just install the stub code/page at the top of the (inner) address space, i.e. put it just above TASK_SIZE. The pages are simply hard-coded to be mapped in the userspace process we use to implement an mm context, and they're out of reach of the inner mmap/munmap/mprotect etc. since they're above TASK_SIZE. Getting rid of the VMA also makes vma_merge() no longer hit one of the VM_WARN_ON()s there because we installed a VMA while the code assumes the stack VMA is the first one. It also removes a lockdep warning about mmap_sem usage since we no longer have uml_setup_stubs() and thus no longer need to do any manipulation that would require mmap_sem in activate_mm(). Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2021-02-12um: rework userspace stubs to not hard-code stub locationGravatar Johannes Berg 1-2/+1
The userspace stacks mostly have a stack (and in the case of the syscall stub we can just set their stack pointer) that points to the location of the stub data page already. Rework the stubs to use the stack pointer to derive the start of the data page, rather than requiring it to be hard-coded. In the clone stub, also integrate the int3 into the stack remap, since we really must not use the stack while we remap it. This prepares for putting the stub at a variable location that's not part of the normal address space of the userspace processes running inside the UML machine. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2021-02-12um: separate child and parent errors in clone stubGravatar Johannes Berg 1-14/+11
If the two are mixed up, then it looks as though the parent returned an error if the child failed (before) the mmap(), and then the resulting process never gets killed. Fix this by splitting the child and parent errors, reporting and using them appropriately. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2020-10-26arch/um: partially revert the conversion to __section() macroGravatar Linus Torvalds 1-1/+1
A couple of um files ended up not including the header file that defines the __section() macro, and the simplest fix is to just revert the change for those files. Fixes: 33def8498fdd treewide: Convert macro and uses of __section(foo) to __section("foo") Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net> Cc: Joe Perches <joe@perches.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-25treewide: Convert macro and uses of __section(foo) to __section("foo")Gravatar Joe Perches 1-1/+1
Use a more generic form for __section that requires quotes to avoid complications with clang and gcc differences. Remove the quote operator # from compiler_attributes.h __section macro. Convert all unquoted __section(foo) uses to quoted __section("foo"). Also convert __attribute__((section("foo"))) uses to __section("foo") even if the __attribute__ has multiple list entry forms. Conversion done using the script at: https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09mmap locking API: convert mmap_sem commentsGravatar Michel Lespinasse 1-1/+1
Convert comments that reference mmap_sem to reference mmap_lock instead. [akpm@linux-foundation.org: fix up linux-next leftovers] [akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil] [akpm@linux-foundation.org: more linux-next fixups, per Michel] Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09mm: don't include asm/pgtable.h if linux/mm.h is already includedGravatar Mike Rapoport 2-2/+0
Patch series "mm: consolidate definitions of page table accessors", v2. The low level page table accessors (pXY_index(), pXY_offset()) are duplicated across all architectures and sometimes more than once. For instance, we have 31 definition of pgd_offset() for 25 supported architectures. Most of these definitions are actually identical and typically it boils down to, e.g. static inline unsigned long pmd_index(unsigned long address) { return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address); } These definitions can be shared among 90% of the arches provided XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined. For architectures that really need a custom version there is always possibility to override the generic version with the usual ifdefs magic. These patches introduce include/linux/pgtable.h that replaces include/asm-generic/pgtable.h and add the definitions of the page table accessors to the new header. This patch (of 12): The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the functions involving page table manipulations, e.g. pte_alloc() and pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h> in the files that include <linux/mm.h>. The include statements in such cases are remove with a simple loop: for f in $(git grep -l "include <linux/mm.h>") ; do sed -i -e '/include <asm\/pgtable.h>/ d' $f done Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-29um: syscall.c: include <asm/unistd.h>Gravatar Johannes Berg 1-0/+1
Without CONFIG_SECCOMP, we don't get this include recursively through the existing includes, thus failing the build on not having __NR_syscall_max defined. Add the necessary include to fix this. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2020-03-29um: Implement time-travel=extGravatar Johannes Berg 1-1/+2
This implements synchronized time-travel mode which - using a special application on a unix socket - lets multiple machines take part in a time-travelling simulation together. The protocol for the unix domain socket is defined in the new file include/uapi/linux/um_timetravel.h. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2020-03-29um: Move timer-internal.h to non-sharedGravatar Johannes Berg 1-1/+1
This file isn't really shared, it's only used on the kernel side, not on the user side. Remove the include from the user-side and move the file to a better place. While at it, rename it to time-internal.h, it's not really just timers but all kinds of things related to timekeeping. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2019-12-04um: add support for folded p4d page tablesGravatar Mike Rapoport 2-3/+16
The UML port uses 4 and 5 level fixups to support higher level page table directories in the generic VM code. Implement primitives necessary for the 4th level folding, add walks of p4d level where appropriate and drop usage of __ARCH_USE_5LEVEL_HACK. Link: http://lkml.kernel.org/r/1572938135-31886-13-git-send-email-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Anatoly Pugachev <matorola@gmail.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Mark Salter <msalter@redhat.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Peter Rosin <peda@axentia.se> Cc: Richard Weinberger <richard@nod.at> Cc: Rolf Eike Beer <eike-kernel@sf-tec.de> Cc: Russell King <linux@armlinux.org.uk> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Sam Creasey <sammy@sammy.net> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-10-10seccomp: simplify secure_computing()Gravatar Christian Brauner 1-1/+1
Afaict, the struct seccomp_data argument to secure_computing() is unused by all current callers. So let's remove it. The argument was added in [1]. It was added because having the arch supply the syscall arguments used to be faster than having it done by secure_computing() (cf. Andy's comment in [2]). This is not true anymore though. /* References */ [1]: 2f275de5d1ed ("seccomp: Add a seccomp_data parameter secure_computing()") [2]: https://lore.kernel.org/r/CALCETrU_fs_At-hTpr231kpaAd0z7xJN4ku-DvzhRU6cvcJA_w@mail.gmail.com Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Drewry <wad@chromium.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-parisc@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linux-um@lists.infradead.org Cc: x86@kernel.org Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20190924064420.6353-1-christian.brauner@ubuntu.com Signed-off-by: Kees Cook <keescook@chromium.org>
2019-09-15um: Add SPDX headers to files in arch/um/kernel/Gravatar Alex Dewar 6-6/+6
Convert files to use SPDX header. All files are licensed under the GPLv2. Signed-off-by: Alex Dewar <alex.dewar@gmx.co.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2019-09-15um: Implement TRACE_IRQFLAGS_SUPPORTGravatar Johannes Berg 2-3/+3
UML enables TRACE_IRQFLAGS_SUPPORT but doesn't actually implement it. It seems to have been added for lockdep support, but that can't actually really work well without IRQ flags tracing, as is also very noisily reported when enabling CONFIG_DEBUG_LOCKDEP. Implement it now. Fixes: 711553efa5b8 ("[PATCH] uml: declare in Kconfig our partial LOCKDEP support") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2019-07-14Merge tag 'for-linus-5.3-rc1' of ↵Gravatar Linus Torvalds 2-0/+13
git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml Pull UML updates from Richard Weinberger: - A new timer mode, time travel, for testing with UML - Many bugixes/improvements for the serial line driver - Various bugfixes * tag 'for-linus-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: fix build without CONFIG_UML_TIME_TRAVEL_SUPPORT um: Fix kcov crash during startup um: configs: Remove useless UEVENT_HELPER_PATH um: Support time travel mode um: Pass nsecs to os timer functions um: Remove drivers/ssl.h um: Don't garbage collect in deactivate_all_fds() um: Silence lockdep complaint about mmap_sem um: Remove locking in deactivate_all_fds() um: Timer code cleanup um: fix os_timer_one_shot() um: Fix IRQ controller regression on console read
2019-07-02um: Fix kcov crash during startupGravatar Marek Majkowski 1-0/+2
Kcov fails to start when compiled with kcov. Disable KCOV on arch/uml/kernel/skas. $ gdb -q -ex r ./vmlinux Program received signal SIGSEGV, Segmentation fault. check_kcov_mode (t=<>, needed_mode=<>) at kernel/kcov.c:70 70 mode = READ_ONCE(t->kcov_mode); Signed-off-by: Marek Majkowski <marek@cloudflare.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2019-07-02um: Support time travel modeGravatar Johannes Berg 1-0/+11
Sometimes it can be useful to run with "time travel" inside the UML instance, for example for testing. For example, some tests for the wireless subsystem and userspace are based on hwsim, a virtual wireless adapter. Some tests can take a long time to run because they e.g. wait for 120 seconds to elapse for some regulatory checks. This obviously goes faster if it need not actually wait that long, but time inside the test environment just "bumps up" when there's nothing to do. Add CONFIG_UML_TIME_TRAVEL_SUPPORT to enable code to support such modes at runtime, selected on the command line: * just "time-travel", in which time inside the UML instance can move faster than real time, if there's nothing to do * "time-travel=inf-cpu" in which time also moves slower and any CPU processing takes no time at all, which allows to implement consistent behaviour regardless of host CPU load (or speed) or debug overhead. An additional "time-travel-start=<seconds>" parameter is also supported in this case to start the wall clock at this time (in unix epoch). With this enabled, the test mentioned above goes from a runtime of about 140 seconds (with startup overhead and all) to being CPU bound and finishing in 15 seconds (on my slow laptop). Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2019-05-27signal: Remove task parameter from force_sigsegvGravatar Eric W. Biederman 1-1/+1
The function force_sigsegv is always called on the current task so passing in current is redundant and not passing in current makes this fact obvious. This also makes it clear force_sigsegv always calls force_sig on the current task. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2019-05-07um: remove unused variableGravatar Bartosz Golaszewski 1-1/+0
The buf variable is unused. Remove it. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Reviewed-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2018-12-27um: Remove unnecessary faulted check in uaccess.cGravatar Anton Ivanov 1-11/+12
It is not necessary to check if a fault has occured or not after disabling pagefaults. kmap_atomic does that in all cases and we can disable it for 64 bit where kmap is not needed and a simple page_address would suffice. dd if=/dev/zero of=/dev/null bs=1M count=1M Before: 3.1GB/s. After: 3.5GB/s There is a noticeable difference for file disk read and write as well as less noticeable difference for network IO. Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2017-03-28um: switch to RAW_COPY_USERGravatar Al Viro 1-4/+4
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-28new helper: uaccess_kernel()Gravatar Al Viro 1-5/+5
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-02sched/headers: Prepare to move 'init_task' and 'init_thread_union' from ↵Gravatar Ingo Molnar 1-0/+1
<linux/sched.h> to <linux/sched/task.h> Update all usage sites first. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02sched/headers: Prepare to remove the <linux/mm_types.h> dependency from ↵Gravatar Ingo Molnar 1-1/+2
<linux/sched.h> Update code that relied on sched.h including various MM types for them. This will allow us to remove the <linux/mm_types.h> include from <linux/sched.h>. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Gravatar Ingo Molnar 1-0/+1
<linux/sched/task_stack.h> We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task_stack.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Gravatar Ingo Molnar 1-1/+2
<linux/sched/signal.h> We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/signal.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-07um/ptrace: Fix the syscall number update after a ptraceGravatar Mickaël Salaün 1-5/+0
Update the syscall number after each PTRACE_SETREGS on ORIG_*AX. This is needed to get the potentially altered syscall number in the seccomp filters after RET_TRACE. This fix four seccomp_bpf tests: > [ RUN ] TRACE_syscall.skip_after_RET_TRACE > seccomp_bpf.c:1560:TRACE_syscall.skip_after_RET_TRACE:Expected -1 (18446744073709551615) == syscall(39) (26) > seccomp_bpf.c:1561:TRACE_syscall.skip_after_RET_TRACE:Expected 1 (1) == (*__errno_location ()) (22) > [ FAIL ] TRACE_syscall.skip_after_RET_TRACE > [ RUN ] TRACE_syscall.kill_after_RET_TRACE > TRACE_syscall.kill_after_RET_TRACE: Test exited normally instead of by signal (code: 1) > [ FAIL ] TRACE_syscall.kill_after_RET_TRACE > [ RUN ] TRACE_syscall.skip_after_ptrace > seccomp_bpf.c:1622:TRACE_syscall.skip_after_ptrace:Expected -1 (18446744073709551615) == syscall(39) (26) > seccomp_bpf.c:1623:TRACE_syscall.skip_after_ptrace:Expected 1 (1) == (*__errno_location ()) (22) > [ FAIL ] TRACE_syscall.skip_after_ptrace > [ RUN ] TRACE_syscall.kill_after_ptrace > TRACE_syscall.kill_after_ptrace: Test exited normally instead of by signal (code: 1) > [ FAIL ] TRACE_syscall.kill_after_ptrace Fixes: 26703c636c1f ("um/ptrace: run seccomp after ptrace") Signed-off-by: Mickaël Salaün <mic@digikod.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: James Morris <jmorris@namei.org> Cc: user-mode-linux-devel@lists.sourceforge.net Signed-off-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-09-07um/ptrace: Fix the syscall_trace_leave callGravatar Mickaël Salaün 1-2/+3
Keep the same semantic as before the commit 26703c636c1f: deallocate audit context and fake a proper syscall exit. This fix a kernel panic triggered by the seccomp_bpf test: > [ RUN ] global.ERRNO_valid > BUG: failure at kernel/auditsc.c:1504/__audit_syscall_entry()! > Kernel panic - not syncing: BUG! Fixes: 26703c636c1f ("um/ptrace: run seccomp after ptrace") Signed-off-by: Mickaël Salaün <mic@digikod.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: James Morris <jmorris@namei.org> Cc: user-mode-linux-devel@lists.sourceforge.net Signed-off-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-06-14um/ptrace: run seccomp after ptraceGravatar Kees Cook 1-5/+4
Close the hole where ptrace can change a syscall out from under seccomp. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: user-mode-linux-devel@lists.sourceforge.net
2016-06-14seccomp: Add a seccomp_data parameter secure_computing()Gravatar Andy Lutomirski 1-1/+1
Currently, if arch code wants to supply seccomp_data directly to seccomp (which is generally much faster than having seccomp do it using the syscall_get_xyz() API), it has to use the two-phase seccomp hooks. Add it to the easy hooks, too. Cc: linux-arch@vger.kernel.org Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-03-17mm: cleanup *pte_alloc* interfacesGravatar Kirill A. Shutemov 1-1/+1
There are few things about *pte_alloc*() helpers worth cleaning up: - 'vma' argument is unused, let's drop it; - most __pte_alloc() callers do speculative check for pmd_none(), before taking ptl: let's introduce pte_alloc() macro which does the check. The only direct user of __pte_alloc left is userfaultfd, which has different expectation about atomicity wrt pmd. - pte_alloc_map() and pte_alloc_map_lock() are redefined using pte_alloc(). [sudeep.holla@arm.com: fix build for arm64 hugetlbpage] [sfr@canb.auug.org.au: fix arch/arm/mm/mmu.c some more] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-10um: Add seccomp supportGravatar Mickaël Salaün 1-0/+5
This brings SECCOMP_MODE_STRICT and SECCOMP_MODE_FILTER support through prctl(2) and seccomp(2) to User-mode Linux for i386 and x86_64 subarchitectures. secure_computing() is called first in handle_syscall() so that the syscall emulation will be aborted quickly if matching a seccomp rule. This is inspired from Meredydd Luff's patch (https://gerrit.chromium.org/gerrit/21425). Signed-off-by: Mickaël Salaün <mic@digikod.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: James Hogan <james.hogan@imgtec.com> Cc: Meredydd Luff <meredydd@senatehouse.org> Cc: David Drysdale <drysdale@google.com> Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Kees Cook <keescook@chromium.org>
2016-01-10um: Fix ptrace GETREGS/SETREGS bugsGravatar Mickaël Salaün 1-12/+14
This fix two related bugs: * PTRACE_GETREGS doesn't get the right orig_ax (syscall) value * PTRACE_SETREGS can't set the orig_ax value (erased by initial value) Get rid of the now useless and error-prone get_syscall(). Fix inconsistent behavior in the ptrace implementation for i386 when updating orig_eax automatically update the syscall number as well. This is now updated in handle_syscall(). Signed-off-by: Mickaël Salaün <mic@digikod.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: Thomas Meyer <thomas@m3y3r.de> Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: Anton Ivanov <aivanov@brocade.com> Cc: Meredydd Luff <meredydd@senatehouse.org> Cc: David Drysdale <drysdale@google.com> Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Kees Cook <keescook@chromium.org>
2015-11-06um: Switch clocksource to hrtimersGravatar Anton Ivanov 2-5/+4
UML is using an obsolete itimer call for all timers and "polls" for kernel space timer firing in its userspace portion resulting in a long list of bugs and incorrect behaviour(s). It also uses ITIMER_VIRTUAL for its timer which results in the timer being dependent on it running and the cpu load. This patch fixes this by moving to posix high resolution timers firing off CLOCK_MONOTONIC and relaying the timer correctly to the UML userspace. Fixes: - crashes when hosts suspends/resumes - broken userspace timers - effecive ~40Hz instead of what they should be. Note - this modifies skas behavior by no longer setting an itimer per clone(). Timer events are relayed instead. - kernel network packet scheduling disciplines - tcp behaviour especially under load - various timer related corner cases Finally, overall responsiveness of userspace is better. Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Anton Ivanov <aivanov@brocade.com> [rw: massaged commit message] Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-06um: Get rid of open coded NR_SYSCALLSGravatar Richard Weinberger 1-5/+3
We can use __NR_syscall_max. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-06um: Store syscall number after syscall_trace_enter()Gravatar Richard Weinberger 1-10/+3
To support changing syscall numbers we have to store it after syscall_trace_enter(). Signed-off-by: Richard Weinberger <richard@nod.at>
2015-05-31um: Handle tracehook_report_syscall_entry() resultGravatar Richard Weinberger 1-1/+5
tracehook_report_syscall_entry() is allowed to fail, in case of failure we have to abort the current syscall. Signed-off-by: Richard Weinberger <richard@nod.at>